The increasing number of computer systems that are interconnected with other computer systems in computer networks and the increasing complexity of such networks have made the task of protecting computer systems from vulnerabilities increasingly difficult and costly. Data security-related issues that an enterprise might face include authentication and authorization of users, encryption of files and messages, digital rights management, filtering of unwanted content, and compliance with regulations and other standards. The encryption of files and messages, in particular, is seen as an effective means of protecting sensitive data.